Sodium tanshinone IIA sulfonate suppresses pulmonary fibroblast proliferation and activation induced by silica: role of the Nrf2/Trx pathway

Modulation in NF-κB-p65/NLRP3, TXNIP-mediated signaling using an ethanolic fruit extract of Withania coagulans mitigates silica-induced pulmonary fibrosis in rats

Withania coagulans encompasses many active phytoconstituents, which have been used to treat many ailments. Prior research has shown that fruit extract of Withania coagulans has anti-inflammatory properties and effectively reduces oxidative stress in various diseases. Nevertheless, its effects are not obscured in the silica (SiO2) induced pulmonary fibrosis (PF). In the current study, an ethanolic fruit extract of Withania coagulans (WCE) was prepared, and its effects and underlying mechanisms on SiO2-induced PF in rats were elucidated. LC-MS/MS analysis identified various bioactive phytoconstituents, secondary plant metabolites, and flavonoids in the WCE. In vitro, results showed that the WCE exhibited no toxicity towards A549 cells, reduced the production of reactive oxygen species, and inhibited cell migration. Further, WCE abrogated alveolar wall thickening, reduced inflammatory cell infiltration, and maintained lung architecture. It also suppresses collagen accumulation and mucus production, abrogating inflammation by downregulating nuclear factor kappa B (NF-κB-p65)/ NOD-like receptor protein 3 (NLRP3) and cytokine levels. It suppresses oxidative and endoplasmic reticulum stress induced by SiO2 by downregulating thioredoxin-interacting protein (TXNIP), activating transcription factor 6 (ATF6), and C/EBP Homologous Protein (CHOP) proteins. Additionally, WCE, by suppressing EMT and transforming growth factor beta 1 (TGF-β1)/Suppressor of Mothers against Decapentaplegic (Smad) pathway, mitigated PF in rats. Taken together, WCE via anti-inflammatory and anti-oxidative properties inhibited SiO2-induced PF, and therefore, it can be envisaged as an effective antifibrotic agent to treat PF.

Silica-induced ROS in alveolar macrophages and its role on the formation of pulmonary fibrosis via polarizing macrophages into M2 phenotype: a review

Alveolar macrophages (AMs), the first line against the invasion of foreign invaders, play a predominant role in the pathogenesis of silicosis. Studies have shown that inhaled silica dust is recognized and engulfed by AMs, resulting in the production of large amounts of silica-induced reactive oxygen species (ROS), including particle-derived ROS and macrophage-derived ROS. These ROS change the microenvironment of the AMs where the macrophage phenotype is stimulated to swift from M0 to M1 and/or M2, and ultimately emerge as the M2 phenotype to trigger silicosis. This is a complex process accompanied by various molecular biological events. Unfortunately, the detailed processes and mechanisms have not been systematically described. In this review, we first systematically introduce the process of ROS induced by silica in AMs. Then, describe the role and molecular mechanism of M2-type macrophage polarization caused by silica-induced ROS. Finally, we review the mechanism of pulmonary fibrosis induced by M2 polarized AMs. We conclude that silica-induced ROS initiate the fibrotic process of silicosis by inducing macrophage into M2 phenotype, and that targeted intervention of silica-induced ROS in AMs can reprogram the macrophage polarization and ameliorate the pathogenesis of silicosis.

Transcriptomic profiling of lung fibroblasts in silicosis: Regulatory roles of Nrf2 agonists in a mouse model

Silicosis is an occupational disease caused by long-term inhalation of free silica, resulting in a significant global health burden. Its pathogenesis remains unclear, and there is no effective treatment. Proliferative and activated myofibroblasts play a key role in the development of silicosis. Traditional studies have focused on fibroblast proliferation and collagen secretion, neglecting their functional heterogeneity. With the advancement of omics research, more pathogenic fibroblast subgroups and their functions have been identified. In this study, we applied transcriptomics to analyze gene changes in primary lung fibroblasts during silicosis development using a mouse model. Our results indicate that DEGs are enriched in collagen secretion, ECM synthesis, leukocyte migration, and chemotaxis functions. Altered core genes are associated with immune cell recruitment and cell migration. Nrf2 agonists, known for anti-inflammatory and antioxidant properties, have shown potential therapeutic effects in fibrotic diseases. However, their effects on fibroblasts in silicosis are not fully understood. We used four common Nrf2 agonists to study gene expression changes in lung fibroblasts at the transcriptome level, combined with histopathological and biochemical methods, to investigate their effects on silicosis in mice. Results show that Nrf2 agonists can exert anti-silicosis fibrosis functions by downregulating genes like Fos and Egr1, involved in cell differentiation, proliferation, and inflammation. In conclusion, this study suggests that inflammation-related co-functions of fibroblasts may be a potential mechanism in silicosis pathogenesis. Targeting Nrf2 may be a promising strategy to alleviate oxidative stress and inflammation in silicosis.

Repeated Silica exposures lead to Silicosis severity via PINK1/PARKIN mediated mitochondrial dysfunction in mice model

BACKGROUND AND OBJECTIVES

Silicosis, one of the occupational health illnesses is caused by inhalation of crystalline silica. Deposition of extracellular matrix and fibroblast proliferation in lungs are linked to silicosis development. Mitochondrial dysfunction plays critical role in some diseases, but how these processes progress and regulated in silicosis, remains limited. Detailed study of silica induced pulmonary fibrosis in mouse model, its progression and severity may be helpful in designing future therapeutic strategies.

METHODS

In present study, mice model of silicosis has been developed after repeated silica exposures which may closely resemble clinical symptoms of silicosis in human. In addition to efficiently mimicking the acute/chronic transformation processes of silicosis, this is practical and efficient in terms of time and output, which avoids mechanical injury to the upper respiratory tract due to surgical interventions. Sonicated sterile silica suspension (120 mg/kg) was administered through intranasal route thrice a week at regular intervals (21, 28 and 35 days).

RESULTS

Presence of minute to larger silicotic nodules in H&E-stained lung sections were observed in all silica induced model groups. Enhanced ECM deposition was noted in MT stained lung sections of silica exposure groups as compared to control which were confirmed by significantly higher MMP9 expression levels and hydroxyproline content in silica 35 days group. Increase in Reactive oxygen species (ROS), inflammatory cell recruitment mainly, neutrophils and macrophage were observed in all three silica exposure groups. Transmission electron microscopic analysis has confirmed presence of many aberrant shaped mitochondria (swollen, round shape) in 35 days model where autophagosomes were minimum. Western blot analysis of mitophagy and autophagy markers such as Pink1, Parkin, Cytochrome c, SQSTM1/p62, the ratio of light chain LC3B II/LC3B I was found higher in 21 and 28 days which were significantly reduced in 35 days silica model.

CONCLUSIONS

Higher MMP9 activity and MMP9 /TIMP1 ratio demonstrate excessive extracellular matrix damage and deposition in 35 days model. Significantly reduced expressions of autophagy and mitophagy markers have also confirmed progression in fibrosis severity and its association with repeated silica exposures in 35 days model group.

Simvastatin attenuates silica-induced pulmonary inflammation and fibrosis in rats via the AMPK-NOX pathway

BACKGROUND

Simvastatin (Sim), a hydroxy-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, has been widely used in prevention and treatment of cardiovascular diseases. Studies have suggested that Sim exerts anti-fibrotic effects by interfering fibroblast proliferation and collagen synthesis. This study was to determine whether Sim could alleviate silica-induced pulmonary fibrosis and explore the underlying mechanisms.

METHODS

The rat model of silicosis was established by the tracheal perfusion method and treated with Sim (5 or 10 mg/kg), AICAR (an AMPK agonist), and apocynin (a NOX inhibitor) for 28 days. Lung tissues were collected for further analyses including pathological histology, inflammatory response, oxidative stress, epithelial mesenchymal transformation (EMT), and the AMPK-NOX pathway.

RESULTS

Sim significantly reduced silica-induced pulmonary inflammation and fibrosis at 28 days after administration. Sim could reduce the levels of interleukin (IL)-1β, IL-6, tumor necrosis factor-α and transforming growth factor-β1 in lung tissues. The expressions of hydroxyproline, α-SMA and vimentin were down-regulated, while E-cad was increased in Sim-treated rats. In addition, NOX4, p22pox, p40phox, p-p47phox/p47phox expressions and ROS levels were all increased, whereas p-AMPK/AMPK was decreased in silica-induced rats. Sim or AICAR treatment could notably reverse the decrease of AMPK activity and increase of NOX activity induced by silica. Apocynin treatment exhibited similar protective effects to Sim, including down-regulating of oxidative stress and inhibition of the EMT process and inflammatory reactions.

CONCLUSIONS

Sim attenuates silica-induced pulmonary inflammation and fibrosis by downregulating EMT and oxidative stress through the AMPK-NOX pathway.

The role of inflammation in silicosis

Silicosis is a chronic illness marked by diffuse fibrosis in lung tissue resulting from continuous exposure to SiO2-rich dust in the workplace. The onset and progression of silicosis is a complicated and poorly understood pathological process involving numerous cells and molecules. However, silicosis poses a severe threat to public health in developing countries, where it is the most prevalent occupational disease. There is convincing evidence supporting that innate and adaptive immune cells, as well as their cytokines, play a significant role in the development of silicosis. In this review, we describe the roles of immune cells and cytokines in silicosis, and summarize current knowledge on several important inflammatory signaling pathways associated with the disease, aiming to provide novel targets and strategies for the treatment of silicosis-related inflammation.

The thioredoxin expression of Cristaria plicata is regulated by Nrf2/ARE pathway under microcystin stimulation

Thioredoxin plays an important role in inhibiting apoptosis and protecting cells from oxidative stress. This study was aimed to clarify how the expression of Trx from Cristaria plicata is regulated by Nrf2/ARE pathway. The expression of CpTrx mRNA was significantly up-regulated in gill and kidney tissues under microcystin stress. The Nrf2 gene of Cristaria plicata was identified to possess an auto active domain bit. While CpNrf2 was knocked down by specific small RNA, CpTrx mRNA expression was significantly down-regulated. The promoter of CpTrx gene had high transcriptional activity, and this basic transcriptional activity persisted after ARE element mutation. The region of promoter -206 to +217 bp was a core promoter region and had forward regulatory elements. Gel shift Assay exhibited that the CpTrx promoter could bind to the purified proteins CpNrf2 and CpMafK in vitro. The binding phenomenon disappeared after the ARE element mutation in promoter region. Subcellular localization experiments displayed that fluorescence overlap between CpNrf2 and Trx promoter increased under microcystin toxin stress. These results suggested that Trx expression was regulated by Nrf2/ARE pathway under oxidative stress.

Yangqing Chenfei formula attenuates silica-induced pulmonary fibrosis by suppressing activation of fibroblast via regulating PI3K/AKT, JAK/STAT, and Wnt signaling pathway

BACKGROUND

Yangqing Chenfei formula (YCF) has been demonstrated its clinical efficiency on silicosis patients. However, the effect of YCF against silicotic fibrosis and its mechanism remain unclear.

PURPOSE

This study is aimed to investigate active compounds and molecular mechanism of YCF in treating silicosis.

METHOD

YCF was orally administrated to silicosis rats induced by crystalline silica. The effective fraction of YCF and the compounds was isolated and identified by using macroporous resin and HPLC-MS, respectively. The targets and potential molecular mechanism of YCF against silicotic fibrosis were investigated through pharmacological network and RNA-sequencing analysis and in vitro-experimental validation.

RESULTS

YCF could remarkably improve the lung function and pathological changes of silicotic rats, reduce the aggregation of fibrocytes and deposition of ECM, such as collagen I, III, FN, and α-SMA, and suppress the TGF-β/Smad3 signaling. Furthermore, YCF6, the effective fraction derived from YCF, could significantly inhibit fibroblast activation induced by TGF-β. Then, 135 compounds were identified from YCF6 by using HPLC-MS, and Network pharmacology analysis predicted total 941 targets for these compounds. Moreover, 409 differentially expressed genes of fibroblast activation induced by TGF-β were identified. Then, integrated analysis of the 941 targets with 409 differentially expressed genes showed that YCF6 contains multiple compounds, such as tangeretin, L-Malic acid, 2-Monolinolein etc., which inhibits fibroblast activation probably by targeting different proteins, such as PIK3CA, AKT1, JAK2, STAT3, GSK3β, leading to regulate the signal network, such as PI3K/AKT signaling pathway, JAK/STAT signaling pathway, and Wnt signaling pathway. Finally, in vitro experiment indicated that tangeretin, the active compound contained in YCF6, could significantly inhibit TGF-β induced fibroblast activation. Moreover, YCF6 and tangeretin could markedly inhibit the activation of PI3K/AKT, JAK/STAT, and Wnt pathway.

CONCLUSION

YCF contained multiple compounds and targeted various proteins that regulated the fibroblast activation, which might be the molecular mechanisms of it in treating silicosis.

Combined intervention with N-acetylcysteine and desipramine alleviated silicosis development by regulating the Nrf2/HO-1 and ASMase/ceramide signaling pathways

Silicosis is a systemic disease characterized by diffuse fibrosis of the lung tissue caused by long-term inhalation of large amounts of free silica (SiO₂) dust. The pathogenesis of silicosis has not been fully elucidated, and there is a lack of effective treatment methods. N-acetylcysteine (NAC) can potentially treat pulmonary fibrosis by exerting antioxidant effects. Desipramine (DMI) can influence pulmonary fibrosis development by inhibiting acid sphingomyelinase (ASMase) activity and regulating ceramide concentrations. Both can interfere with pulmonary fibrosis through different mechanisms, but the intervention effects of NAC combined with DMI on silicosis fibrosis have not been reported. Therefore, this study established a rat silicosis model using a single tracheal drip of SiO₂ dust suspension in Wistar rats to investigate the effect of NAC combined with DMI on SiO₂ dust-induced silicosis and its related molecular mechanisms. The histopathological examination of the SiO₂ dust-induced silicosis rats suggested that NAC and DMI alone or in combination could decrease the severity of pulmonary fibrosis in rats. The combined intervention had a better effect on reducing fibrosis than the individual interventions. NAC and DMI, alone or in combination, decreased the levels of markers related to pulmonary fibrosis in rats (smooth muscle α-actin (α-SMA), collagen (Col) I, Col III, hydroxyproline (HYP), inflammatory factors (transforming growth factor-β1 (TGF-β1) and tumor necrosis factor-α (TNF-α)), and lipid peroxidase malondialdehyde (MDA)). The nuclear factor-erythroid 2-related factor 2 (Nrf2)/heme-oxygenase-1 (HO-1) and ASMase/ceramide pathways were inhibited to some extent by increasing the superoxide dismutase (SOD) levels of antioxidant enzymes and 8-iso-prostaglandin F2α (8-iso-PGF2α) levels of lipid peroxides. The combined intervention and NAC alone inhibited the SiO₂ dust-induced elevation of matrix metalloproteinase 1 (MMP-1) and tissue inhibitor matrix metalloproteinase 1 (TIMP-1), but the effect was not significant in the DMI-treated group. Combining DMI and NAC inhibited Col I deposition and reduced HO-1, TIMP-1, and ASMase levels in lung tissues compared to individual treatments. In summary, the SiO₂ dust could induce oxidative stress and inflammation in rats, resulting in an imbalance in extracellular matrix (ECM) synthesis/catabolism and ASMase/ceramide signaling pathway activation, leading to silicosis development.The combined intervention of DMI and NAC may synergistically regulate the Nrf2/HO-1 pathway, maintain the anabolic balance of the ECM, inhibit ASMase/ceramide signaling pathway activation by suppressing the inflammatory response and effectively delay silicosis fibrosis progression.

eEF-2K knockdown synergizes with STS treatment to inhibit cell proliferation, migration, and invasion via the TG2/ERK pathway in A549 cells

Emerging research has suggested the anticancer potential of tanshinone IIA, the bioactive ingredient isolated from the traditional Chinese herb Salvia miltiorrhiza. However, the molecular mechanism of sodium tanshinone IIA sulfonate (STS) antilung cancer effect is not very clear. In this study, our purpose is to investigate the roles of STS and elongation factor-2 kinase (eEF-2K) in regulating the proliferation, migration, and invasion of A549 cells and explore the implicated pathways. We found that STS suppressed A549 cell survival and proliferation in a time- and xdose-dependent manner. Knockdown of eEF-2K and treatment with STS synergistically exerted antiproliferative, -migratory, and -invasive effects on A549 cells. These effects were caused by attenuation of the extracellular signal-regulated kinase (ERK) pathway via inhibition of tissue transglutaminase (TG2). In summary, the inhibition of eEF-2K synergizes with STS treatment, exerting anticancer effects on lung adenocarcinoma cells through the TG2/ERK signaling pathway, which provides a potential therapeutic target for treating lung adenocarcinoma.

The Role of Organosulfur Compounds as Nrf2 Activators and Their Antioxidant Effects

Nuclear factor erythroid 2-related factor 2 (Nrf2) signaling has become a key pathway for cellular regulation against oxidative stress and inflammation, and therefore an attractive therapeutic target. Several organosulfur compounds are reportedly activators of the Nrf2 pathway. Organosulfur compounds constitute an important class of therapeutic agents in medicinal chemistry due to their ability to participate in biosynthesis, metabolism, cellular functions, and protection of cells from oxidative damage. Sulfur has distinctive chemical properties such as a large number of oxidation states and versatility of reactions that promote fundamental biological reactions and redox biochemistry. The presence of sulfur is responsible for the peculiar features of organosulfur compounds which have been utilized against oxidative stress-mediated diseases. Nrf2 activation being a key therapeutic strategy for oxidative stress is closely tied to sulfur-based chemistry since the ability of compounds to react with sulfhydryl (-SH) groups is a common property of Nrf2 inducers. Although some individual organosulfur compounds have been reported as Nrf2 activators, there are no papers with a collective analysis of these Nrf2-activating organosulfur compounds which may help to broaden the knowledge of their therapeutic potentials and motivate further research. In line with this fact, for the first time, this review article provides collective and comprehensive information on Nrf2-activating organosulfur compounds and their therapeutic effects against oxidative stress, thereby enriching the chemical and pharmacological diversity of Nrf2 activators.

Targeting Oxidative Stress as a Therapeutic Approach for Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease characterized by an abnormal reepithelialisation, an excessive tissue remodelling and a progressive fibrosis within the alveolar wall that are not due to infection or cancer. Oxidative stress has been proposed as a key molecular process in pulmonary fibrosis development and different components of the redox system are altered in the cellular actors participating in lung fibrosis. To this respect, several activators of the antioxidant machinery and inhibitors of the oxidant species and pathways have been assayed in preclinical in vitro and in vivo models and in different clinical trials. This review discusses the role of oxidative stress in the development and progression of IPF and its underlying mechanisms as well as the evidence of oxidative stress in human IPF. Finally, we analyze the mechanism of action, the efficacy and the current status of different drugs developed to inhibit the oxidative stress as anti-fibrotic therapy in IPF.

Active Components from Traditional Herbal Medicine for the Potential Therapeutics of Idiopathic Pulmonary Fibrosis: A Systemic Review

Idiopathic pulmonary fibrosis (IPF), a tumor-like disease, is a serious and fatal pulmonary inflammatory condition usually characterized by irreversible destruction of the lung parenchyma, excessive matrix accumulation, and decline in lung function. IPF still remains a great burden to the universe. At the moment, the available therapeutic regimens utilized for IPF such as non-pharmacological therapies (lung transplantation) and pharmacological therapies (drugs, nintedanib, pirfenidone, etc.) are normally accompanied by significant limitations, such as adverse reactions, low bioavailability, poor selectivity, low-tissue distribution, in vivo instability, systemic toxicity, inconveniency and unsafe usage. There is a need for the exploration and discovery of new novel remedies by researchers and scientists globally. Recent numerous preliminary studies have laid significant emphasis and demonstrated the antifibrotic importance, good curative actions (little or no adverse reactions), and multiple target sites of the active components from traditional herbal medicine (THM) against IPF, which could serve as a modern, alternative and potential therapeutics or drug candidates in treating IPF. This paper extensively summarizes the pharmacological actions and signaling pathways or mechanisms of active components obtained from THM for treating IPF. Moreover, the sources and modernization, markets, relevant FDA and CFDA studies (the USA and China), preclinical analysis, and various compositions of THM currently under clinical trials are also highlighted. Additionally, this present analytical data would be instrumental towards further drug progression or advancement of active components from THM for the potential therapeutics of IPF in the future.

Nephroprotective effect of gastrodin against lead-induced oxidative stress and inflammation in mice by the GSH, Trx, Nrf2 antioxidant system, and the HMGB1 pathway

Gastrodin (GAS), the main phenolic glycoside derivative from Gastrodiaelata Blume, has several bio-activities. However, the molecular mechanisms of these protective actions currently remain unclear. This study aimed to investigate the mechanisms of GAS on lead (Pb)-induced oxidative stress and inflammation in the kidneys and primary kidney mesangial cells. Results indicated that GAS improved Pb-induced renal dysfunction and morphological changes in mice. GAS ameliorated Pb-induced inflammation in kidneys by reducing the TNF-α and IL-6 levels. GAS inhibited Pb-induced oxidative stress by regulating the glutathione, thioredoxin (Trx), and Nrf2 antioxidant systems. Furthermore, GAS supplementation increased the activation of SOD, GPx, HO-1, and NQO1 in the kidneys. GAS decreased the expression levels of HMGB1, TLR4, RAGE, MyD88, and NF-κB. These results were further confirmed in primary kidney mesangial cells. Collectively, this study demonstrated that GAS alleviated Pb-induced kidney oxidative stress and inflammation by regulating the antioxidant systems and the Nrf2 signaling pathway. Highlights Gastrodin ameliorated Pb-induced kidney injury in mice.Gastrodin inhibited oxidative stress and inflammation in kidneys.Gastrodin activated the GSH, Trx and Nrf2 antioxidant system in kidneys.Gastrodin inhibited the activities of HMGB1. RAGE, TLR4, and MyD88.

Sodium tanshinone IIA sulfonate attenuates silica-induced pulmonary fibrosis in rats via activation of the Nrf2 and thioredoxin system

Silicosis is characterized by pulmonary fibrosis due to long-term inhalation of silica particles. Although the cause of this serious disease is known, its pathogenesis remains unclear and there are currently no specific treatments. Recent studies have shown that the anti-oxidant transcription factor Nrf2 is expressed at reduced levels in fibrotic foci, which may be related to disease progression. However, the molecular mechanisms by which this might occur have yet to be elucidated. Sodium tanshinone IIA sulfonate (STS), an extract of Salvia miltiorrhiza, is used in traditional Chinese medicine in the treatment of coronary heart disease. STS has been shown to play a strong anti-oxidative role in various organs. Here, we employed a rat model to explore the effects of STS on oxidative stress and the progression of fibrosis in silicosis. STS significantly reduced collagen deposition in the lungs, thereby antagonising silicosis. Immunohistochemical and immunofluorescence staining showed that Nrf2 was differentially expressed in lung cells during silica induced fibrosis, and chromatin immunoprecipitation-sequencing experiments demonstrated that Nrf2 promoted the expression of the antioxidant proteins thioredoxin and thioredoxin reductase. Our results suggest that the anti-fibrotic effects of STS may be related to upregulation of Nrf2 nuclear expression, especially in fibrotic lesions, and the promotion of thioredoxin and thioredoxin reductase expression. Our findings may open up new avenues for the development of STS as a treatment for silicosis.

Atractylenolide III attenuates bleomycin-induced experimental pulmonary fibrosis and oxidative stress in rat model via Nrf2/NQO1/HO-1 pathway activation

BACKGROUND

Bleomycin (BLM) is a chemotherapy drug used to treat cancer, one of which side effects is that it can lead to pulmonary fibrosis (PF). Atractylenoide III (AtrIII), derived from the dried roots of rhizoma atractylodis of compositae, is one of the main active substances of rhizoma atractylodis. It has anti-inflammatory, anti-tumor and other effects. This study aimed to investigate whether AtrIII alleviated BLM-induced PF and oxidative stress in rats through the nuclear factor erythroid-2-related factor 2/NQO1,NAD(P)H:quinine oxidoreductase 1/Heme oxygenase-1 (Nrf2/NQO1/HO-1) pathway.

METHODS

A BLM-induced pulmonary fibrosis model in SD rats was established. The respiratory dynamics were evaluated by using Wholebody flow-through plethysmography. Lung injury and pulmonary fibrosis were observed by Hematoxylin-eosin (HE) and Masson staining. Apoptosis was assay by Tunel assay. Inflammatory factors were detected with commercial kits. Expression of mRNAs and proteins were detected by RT-qPCR and Western blot, respectively.

RESULTS

AtrIII (1.2, 2.4 mg/kg) improved the lung injury and lung function in the BLM-induced Sprague-Dawley (SD) rats. AtrIII reduced the apoptosis rate and protein expression of Caspase-3 and Caspase-9. AtrIII (1.2, 2.4 mg/kg) decrease the pulmonary fibrosis damage and protein expression transforming growth factor-β (TGF-β) and α-smooth muscle actin (α-SMA). AtrIII also down-regulated the levels of interleukin 6 (IL-6), inductible nitric oxide synthase (iNOS) and tumor necrosis factor-α (TNF-α), while up-regulated the level of IL-10 in peripheral blood serum. Moreover, AtrIII (1.2, 2.4 mg/kg) increased the activity of superoxide dismutase (SOD) and glutathione (GSH), while decreased the malondialdehyde (MDA) content and lactate dehydrogenase (LDH) activity. AtrIII (1.2, 2.4 mg/kg) increased the levels of Nrf2, NQO1 and HO-1. In addition, AtrIII reversed the effects of Nrf2 interference on pulmonary fibrosis damage, decreased SOD and GSH activity, and increased MDA content.

CONCLUSION

AtrIII could attenuate the pulmonary fibrosis and reliev oxidative stress through the Nrf2/NQO1/ HO-1 pathway.

Sodium tanshinone IIA sulfonate: A review of pharmacological activity and pharmacokinetics

Sodium tanshinone IIA sulfonate (STS) is a water-soluble derivate of tanshinone IIA (Tan IIA) which is an active lipophilic constitute of Chinese Materia Medica Salvia miltiorrhiza Bge. (Danshen). STS presents multiple pharmacological activities, including anti-oxidant, anti-inflammation and anti-apoptosis, and has been approved for treatment of cardiovascular diseases by China State Food and Drug Administration (CFDA). In this review, we comprehensively summarized the pharmacological activities and pharmacokinetics of STS, which could support the further application and development of STS. In the recent decades, numerous experimental and clinical studies have been conducted to investigate the potential treatment effects of STS in various diseases, such as heart diseases, brain diseases, pulmonary diseases, cancers, sepsis and so on. The underlying mechanisms were most related to anti-oxidative and anti-inflammatory effects of STS via regulating various transcription factors, such as NF-κB, Nrf2, Stat1/3, Smad2/3, Hif-1α and β-catenin. Iron channels, including Ca²⁺, K⁺ and Cl^- channels, were also the important targets of STS. Additionally, we emphasized the differences between STS and Tan IIA despite the interchangeable use of Tan IIA and STS in many previous studies. It is promising to improve the efficacy and reduce side effects of chemotherapeutic drug by the combination use of STS in canner treatment. The application of STS in pregnancy needs to be seriously considered. Moreover, the drug-drug interactions between STS and other drugs needs to be further studied as well as the complications of STS.

Inhibition of nuclear thioredoxin aggregation attenuates PM2.5-induced NF-κB activation and pro-inflammatory responses

Exposure to fine particulate matter (PM_2.5) can induce oxidative stress and proinflammatory cytokine production, which are central for the induction of PM_2.5-mediated adverse effects on public health. Nuclear factor kappa B (NF-κB) signaling is essential for inflammation. The subcellular distribution of thioredoxin (Trx) is related to the activation of NF-κB, but the mechanism involved is unclear. In the current study, we focused on the relationship between the antioxidant Trx and NF-κB in human bronchial epithelial cells (BEAS-2B) after PM_2.5 exposure. We inhibited the nuclear translocation of Trx by cHCEU (4-cyclohexyl-[3-(2-chloroethyl)ureido]benzene) and subsequently increased the transcriptional activity of Nrf2 to upregulate the expression of Trx by t-BHQ. Our data suggest that PM_2.5 exposure induces the activation of NF-κB and the expression of the downstream proinflammatory cytokines IL-1, IL-6, IL-8 and TNF-α in BEAS-2B cells. CHCEU alleviates inflammatory cytokines by blocking Trx nuclear translocation and inhibits the DNA binding activity of NF-κB. T-BHQ could promote the transcriptional activity of Nrf2 but failed to alleviate the production of inflammatory cytokines. Furthermore, the synergistic effect of t-BHQ and cHCEU on alleviating PM_2.5-induced inflammation is more effective than the use of cHCEU alone. Our findings characterize the underlying molecular mechanisms of proinflammatory responses induced by PM_2.5 and show that the nuclear translocation and accumulation of Trx in nuclei play important roles in PM_2.5-induced NF-κB activation and proinflammatory responses.

MicroRNA-29b inhibits supernatants from silica-treated macrophages from inducing extracellular matrix synthesis in lung fibroblasts

Silicosis is pathologically characterized by diffused pulmonary fibrosis and abundant deposition of extracellular matrix (ECM) components. The ECM is mainly secreted by myofibroblasts which are the activated state of fibroblasts. MicroRNA-29b (miR-29b) is one of the well-known microRNAs involved in fibrosis, but its roles in silicosis have not been specified. In this study, we hypothesized that miR-29b might play a protective role in the progression of silicosis. MTT assay, qRT-PCR, immunofluorescence and western blotting were applied. The results demonstrated that the supernatants from silica-treated macrophages not only caused the proliferation of fibroblasts (NIH-3T3 and MRC-5) but were also involved in the down-regulation of miR-29b. Meanwhile they could induce fibroblast activation, increasing the expression of ECM components such as collagen1 and collagen3, in a silica dose-dependent manner. Furthermore, overexpression of miR-29b by transfecting mimics markedly reduced the expression of ECM components and inhibited ECM synthesis. These findings indicate that miR-29b inhibits the supernatants from silica-treated macrophages from inducing extracellular matrix synthesis, thus miR-29b might have a strong anti-fibrotic capacity in silicosis and serve as a potential therapeutic agent for the treatment.